This is a rematch of last year's battle in Detroit, which San Francisco won. However, the story of the game was the handshake between 49ers head coach Jim Harbaugh and Lions head coach Jim Schwartz. As you can see in the video above, the handshake resulted in an altercation between the teams.

This year, both teams enter the matchup after winning their season openers, and the 49ers' impressive victory over the Green Bay Packers has them atop many NFL Power Rankings lists.

The Lions will be in trouble if star wide receiver Calvin Johnson cannot play because of an injury. Here is the latest, according to ESPN's Adam Schefter.

Lions WR Calvin Johnson did not practice today. May be nothing, may be something. Lions will update injury report later.

Without Johnson, the 49ers will be able to dare the Lions to run the ball because quarterback Matthew Stafford will have a much tougher time being successful in the passing game without his No. 1 target.

This is the worst team that the Lions could face without Johnson because the 49ers have the best defense in the NFL. Even if Johnson plays, don't expect the Lions, who struggled to beat an inferior St. Louis Rams team in Week 1, to defeat the 49ers on the road.

The rematch of last year's AFC Championship is one that many fans have had circled on their calendars for months. The Ravens will get another shot to beat the Patriots, this time at home, and a victory for Baltimore would give them an early advantage over New England in the race for the AFC's No. 1 playoff seed.

Both teams are No. 1 and 2 in many experts' AFC power rankings heading into Week 2, and each team has a strong case for the top spot. The outcome of this game will settle the power rankings debate for now.

The last time that New England played in Baltimore, they almost lost their unbeaten record during the 2007 season on Monday Night Football, but escaped with a 27-24 victory.

Expect Ravens linebacker Ray Lewis and the entire Baltimore crowd to be pumped up for this AFC showdown.

This NFC East matchup will be a close game, and even though the New York Giants have been more successful in the playoffs than the Eagles over the last few years, Philadelphia has won six of the last eight regular season meetings against Big Blue.

The Eagles barely beat the Cleveland Browns in Week 1 with quarterback Michael Vick throwing four interceptions before winning the game in the fourth quarter.

The Giants defense, and their front seven in particular, will be a tough matchup for Vick. The Eagles offensive line will need to prevent Vick from getting hit too much, or they could lose him to another injury. Philadelphia is only going to win the Super Bowl if Vick is healthy for an entire season.